Originally Web posted Wednesday, 19 January 2011.
Content last modified Wednesday, 19 January 2011 .
External links last verified Wednesday, 19 January 2011.

Nomai? Oh My!

A Brief Tale of Nomai’s MCD 540S drive and Power Disk Removable Cartridges

Once upon a time in the mid 1990s, a small French company[1] valiantly attempted to bring the world a new record-holder for highest capacity rigid removable disk mass storage. 540 MB was indeed double SyQuest’s then-best of 270 MB, yet CD-Rs already had been born, and it would just be a matter of time before their 650 MB capacity and vastly lower per-disc price would make the non-optical removable disk world fade away. That world was only able to offer the final volley of the SyJet and the Jaz drives, in the 1-2 GB (approximately) range, buying a little time before the 4.7 GB DVD-R wiped the floor with them and put them to rest for all time.

Not long after their introduction, i was working as a QA tester at Apple in Cupertino, California, mostly testing Drive Setup with just about every mass storage drive then known to humanity. This is where i first met the Nomai MCD 540S. By the way, MCD stands for Multimedia Cartridge Drive, 540 is the disk capacity in megabytes, and S is for SCSI. There was also an IDE model, apparently. Anyway… in January 2011 i wound up playing with one of these old drives and its cartridges, and found that there was precious little information about them on the WWW. Before i forget what little i knew/know about them, i thought it worth typing it out, for the other 5 or 10 of you who may come across these and want or need to make them go.

I’m only going to discuss the Nomai MCD in relation to Apple Macintosh products. Nothing personal… it is the platform i know, and so far the only one i use.

Basic Operation

There are some important things to know about the Nomai MCD 540S and its cartridges, including some things not covered in its scanty documentation.

Operating the Protective Storage Case

The case is hinged, and opens thus:

the sections pull apart, hinged at the rear.

It is possible to leave the case closed, pull one of the two latching tabs outward, and get the cartridge out, thought that does not appear to be the method Nomai intended.

Inserting and Ejecting Cartridges

  1. DO NOT Pull On The Door Flap To Open It! This can cause the flap to disengage from the mechanism and cause the drive to not operate (more on this and the fix below)! Press the Eject button on the front of the drive and let the mechanism open the flap, to insert a cartridge.
  2. Insert the cartridge most or all of the way. It does not seem to matter whether it is nearly all the way in, or totally all the way in. As long as the door can close easily, it is in far enough.
  3. Wait for the drive to spin up, get its heads in position, and for its green LED to be lit solid. Note that this takes at least 10 seconds (per Nomai), or much longer (per my personal experience)… be patient! These drives are slow to mount and slow to unmount.
  4. Unmount the disk from the computer OS as usual (drag to the Trash, select Eject or Put Away [Vintage Mac OS]). Then wait patiently for the drive to eject the disk. It will usually push it out at least 1 cm. If the drive fails to push the disk out far enough to grab hold of, push the Eject button on the drive and it ought to push it out further.
  5. Pull the cartridge out the rest of the way by hand and return it to its protective storage case.
  6. The flap on the drive stays down, in preparation for another cartridge being inserted. If you are done, close the flap manually.
Per Nomai:

Disassembly - SCSI External

My MCD 540S is in a generic SCSI case, which i’ve seen holding many different drives over the years… never knew who the case OEM was. In any case (pun if you want it to be), these cases have a sneaky trick for getting inside. It looks like the drive carrier ought to slide right out when the top-of-case latch is depressed, but no… not until you learn the trick:

  1. Remove the left front (as one faces the front of the unit) bottom foot. Pull it off. Watch for holding tabs.
  2. Unscrew the Philips #2 screw hiding under the foot.
  3. Now the carrier will slide out towards the front when the top latch is depressed.

Driver, Mounting

The Nomai MCD 540S follows the standard Vintage Mac removable mass storage device driver operations. Which is to say, if an MCD disk is inserted in the drive at startup (or restart), or if one uses a tool such as SCSIProbe to force the disk to mount, the driver will load and the drive will operate as expected until the next startup or restart.

If one wants the full “works like a floppy disk or CD or DVD disc” experience, where one can insert a cartridge at any time and have it mount (Just Work™) without messing around, one needs to install a (polling) driver, as discussed in the article linked above. In the case of the Nomai MCD 540S on a Vintage Macintosh, that would be Nomai’s original driver. Without much trouble, i found driver versions 1.0.9 and 1.0.11 (apparently the newest/last version) on the WWW via normal searching, in January 2011. These exist as extension files, with the name “MCD Driver”. The original instructions still apply: drag the extension to your Extensions folder (as usual, dragging atop the closed System Folder puts it in the correct location). Both these driver versions are functional under OS 9.1 on a Power Mac 9600/350. They were trouble-free during my brief, perfunctory testing.

Confused? Insufficient information? Check the Standard Vintage Mac Removable Mass Storage Device Driver Operation article.

Cartridge Formatting

If your sole goal is to get data off old MCD cartridges, you’ll not need to get into this. Only people wanting to re-use these cartridges for new data storage are likely to care about reformatting them.

I have not found any information regarding formatting or reformatting Nomai cartridges on a Macintosh. I distinctly remember testing Drive Setup with Nomai drives when i was a QA tester at Apple, as mentioned at the beginning of this article. Yet, having carefully scrutinized the internals of pretty much every version of Drive Setup (DSU) ever released, i find no signs of Nomai support inside (and i do know where to look). Actually trying to use DSU with the Nomai produces the expected result: an unsupported device message, and no ability to format (initialize) it.

I did not experiment with 3rd. party formatters, such as FWB Hard Disk Toolkit, LaCie SilverLining, Anubis, nor others. One or more of those might work.

As best i can tell, Nomai did not foresee the need for the user to reformat the cartridges. Apparently, they figured using the OS Erase command would be sufficient.

Troubleshooting, Error Codes

Actually, that ought to be “Error Code” singular… i only know of one: Two flashes, pause, repeat, along with no spinning nor head positioning sounds (you’ll know… easy to hear even over the case fan). Eventually, the LED switches to a fast flash, then ejects the cartridge. Remember the warning at the beginning of this article regarding not manually pulling down the flap? Wondering how i know about that? Yup… i did it, causing this failure mode.

I had to take the whole drive mechanism apart to figure out the problem. You don’t (most likely)… just keep reading. What happens is that the flap becomes disengaged from the internal mechanism. The cartridge can’t seat properly, so it can’t spin, so the drive can’t operate, and flashes the code.

The solution is to re-engage the flap with the mechanism. The flap snaps onto the mechanism at this point, looking like this when it is properly connected:

The pins on the flap snap into the yokes of the mechanism.

I re-snapped the flap with the whole mechanism apart, so i can’t provide specifics regarding exactly how and what to hold to get the thing snapped back together. Use the photo and your mechanical intuition.

MCD 540S On OS X Macs

Many of you are probably quite interested in this. Many of you are about to be sorely disappointed: I have not tried my MCD 540S on an OS X system. Short answer: i don’t need to… i have a bunch of beige Vintage Macs with built-in SCSI, OS 9, and conversion support to newer formats/OS X Macs via modern communications busses (FireWire, USB, Ethernet). Given the obscurity of these drives (at least in the U.S., where Apple is based) and their short existence as currently-sold items in the marketplace, i highly doubt that they can be made to work with OS X. But i didn’t try, so i don’t really know.

There’s more discussion of this situation generally at the end of the Standard Vintage Mac Removable Mass Storage Device Driver Operation article, in the section Vintage Removable Mass Storage Drives On OS X Macs.

Know Nomai?

Know something about the Nomai MCD 540S that isn’t generally out there on the public Internet, that others may want to know? Feel like sharing it, for possible inclusion on this page, to help others (credit to you or not as you wish)? Let me know. I’ll consider questions, yet what’s already here is pretty much all i know. If you catch me in a good mood and willing to spend the time, i might even try testing something that’s vexing you, if i have all the materials.


[1] Some information in this paragraph comes from the 1995 TidBITS article Apple Expo in Paris.


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